Evaluation of irrigation, drinking, and risk indices for water quality parameters of alpine lakes.

Alpine lakes are aquatic ecosystems that maintain and regulate water supply for the downstream streams, rivers, and other reservoirs. This study examined the water characteristics of various alpine lakes in Gilgit-Baltistan, Northern Pakistan. For this purpose, water was sampled and investigated for basic parameters, anions, and cations using the multi-parameter analyzers and atomic absorption spectrophotometer. Physicochemical parameters of alpine lakes were noted under the World Health Organization water guidelines, except for fluoride (F-) and turbidity in 4.3% and 36% of samples, respectively. Water quality index (WQI) classified samples (93%) as excellent and good quality (7%). Results showed maximum chronic daily intake values (0.14 ± 0.01 mg/kg-day) for nitrate (NO3-) and hazard quotient (0.80 ± 0.24) for F- in children via water intake from Upper Kachura and Shausar Lakes, respectively. Statistical analyses of Piper and Gibbs's plots revealed that the water quality is mainly characterized by bedrock geology.

Optimization of Calcium Fluoride Crystallization Process for Treatment of High-Concentration Fluoride-Containing Semiconductor Industry Wastewater.

This study utilized a fluidized bed reactor (FBR) for fluoride removal from high-concentration fluoride-ion-containing simulated semiconductor industry wastewater and recovered high-purity CaF2 crystals. The effects of hydraulic retention time (HRT), pH, Ca2+ to F- ratio, upflow velocity, seed size and seed bed height were investigated by performing lab-scale batch experiments. Considering fluoride removal and CaF2 crystallization efficiency, 5 h HRT, pH 6, seed height of 50 cm and [Ca2+]/[F-] ratio of 0.55 (mol/mol) were found to be optimum. The effect of the interaction between the important process parameters on fluoride removal was further analyzed using response surface methodology (RSM) experimental design. The results showed that all the individual parameters have a significant impact (p = 0.0001) on fluoride removal. SEM-EDX and FTIR analysis showed the composition of the crystals formed inside FBR. HR-XRD analysis confirmed that the crystalline structure of samples was mainly CaF2. The results clearly demonstrated the feasibility of silica seed material containing FBR for efficient removal and recovery of fluoride as high-purity calcium fluoride crystals.

Is there any association between fluoride exposure and thyroid function modulation? A systematic review.

Numerous pre-clinical and observational studies have explored the potential effects of fluoride (F) at varying concentrations on diverse systems and organs. While some have assessed the endocrinological conditions of children and adults, a consensus regarding the interaction between F and the thyroid remains elusive. This systematic review aimed to gather primary evidence on the association between F and changes in the thyroid at optimal and high levels in water supply as stipulated by the World Health Organization. A search strategy, incorporating terms pertinent to the studies, was employed across PubMed, Scopus, Web of Science, Lilacs, and Google Scholar. Following the review of studies, data were extracted and analyzed using the Grading of Recommendations, Assessment, Development, and Evaluations to assess the quality of the evidence. Our results yielded 3,568 studies, of which seven met the inclusion criteria for this review. Five of the seven studies identified an association between high F exposure and thyroid function. In the analysis of methodological quality, every study was found to have major or minor methodological issues and significant risk of bias. The overall confidence in the evidence was deemed low for all outcomes in the seven studies. The evidence compiled in this review suggests a potential association between chronic high levels of F exposure and thyroid damage. Nonetheless, further studies with robust design and high methodological quality are required to provide evidence for policy makers and health care practitioners.

Effect of bottled fluoridated water to prevent dental caries in primary teeth: study protocol for a phase 2 parallel-group 3.5-year randomized controlled clinical trial (waterBEST).

BACKGROUND: Fluoridation of public water systems is known as a safe and effective strategy for preventing dental caries based on evidence from non-randomized studies. Yet 110 million Americans do not have access to a fluoridated public water system and many others do not drink tap water. This article describes the study protocol for the first randomized controlled trial (RCT) of fluoridated water that assesses its potential dental caries preventive efficacy when delivered in bottles. METHODS: waterBEST is a phase 2b proof-of-concept, randomized, quadruple-masked, placebo-controlled, parallel-group trial designed to estimate the potential efficacy of fluoridated versus non-fluoridated bottled water to prevent dental caries incidence in the first 4 years of life. Two hundred children living in eastern North Carolina, USA, and aged 2-6 months at screening are being allocated at random in a 1:1 ratio to receive fluoridated (0.7 mg/L F) or non-fluoridated bottled water sourced from two local public water systems. Throughout the 3.5-year intervention, study water is delivered monthly in 5-gallon bottles to each child's home with instructions to use it whenever the child consumes water as a beverage or in food preparation. Parents are interviewed quarterly to monitor children's water consumption and health. At annual visits, the presence of dental caries is evaluated with a dental screening examination. Clippings from fingernails and toenails are collected to quantify fluoride content as a biomarker of total fluoride intake. The primary endpoint is the number of primary tooth surfaces decayed, missing, or filled due to dental caries measured by the study dentist near the time of the child's fourth birthday. Tooth decay is assessed at the threshold of macroscopic enamel loss. For the primary aim, a least-squares, generalized linear model will estimate efficacy and its one-tailed, upper 80% confidence limit. DISCUSSION: waterBEST is the first evaluation of a randomized intervention of fluoridated drinking water in bottles to prevent dental caries in the primary dentition. This innovative method of delivering fluoridated water has the potential to prevent early childhood caries in a large segment of the US population that currently does not benefit from fluoridated public water. TRIAL REGISTRATION: ClinicalTrials.gov NCT04893681. Registered on March 2022. Last update posted on 10 October 2023. https://clinicaltrials.gov/study/NCT04893681?cond=Dental%20Caries%20in%20Children&term=fluoride&locStr=North%20Carolina,%20USA&country=United%20States&state=North%20Carolina&distance=50&rank=1.

Fluoride induces pyroptosis via IL-17A-mediated caspase-1/11-dependent pathways and Bifidobacterium intervention in testis.

Fluoride, a ubiquitous environmental pollutant, poses a significant public health threat. Our previous study revealed a correlation between fluoride-induced testicular pyroptosis and male reproductive dysfunction. However, the underlying mechanism remains unclear. Wild-type and interleukin 17A knockout mice were exposed to sodium fluoride (100 mg/L) in deionized drinking water for 18 weeks. Bifidobacterium intervention (1 × 109 CFU/mL, 0.2 mL/day, administered via gavage) commenced in the 10th week. Sperm quality, testicular morphology, key pyroptosis markers, spermatogenesis key genes, IL-17A signaling pathway, and pyroptosis pathway related genes were determined. The results showed that fluoride reduced sperm quality, damaged testicular morphology, affected spermatogenesis, elevated IL-17A levels, and induced testicular pyroptosis. Bifidobacterium intervention alleviated adverse reproductive outcomes. Fluoride-activated testicular pyroptosis through both typical and atypical pathways, with IL-17A involvement. Bifidobacterium supplementation attenuated pyroptosis by downregulating IL-17A, inhibiting NLRP3 and PYRIN-mediated caspase-1 and caspase-11 dependent pathways in testis, thereby alleviating fluoride-induced male reproductive damage. In summary, this study uncovers the mechanism underlying fluorine-induced testicular pyroptosis and illustrates the novel protecting feature of Bifidobacterium against fluoride-induced harm to male reproduction, along with its potential regulatory mechanism. These results provide fresh perspectives on treating male reproductive dysfunction resulting from fluoride or other environmental toxins.

Laser fluorescence assessment of dental caries arrest with two silver fluoride agents in patients with special needs- a preliminary report.

PURPOSE: While silver diamine fluoride has been used extensively for caries arrest and desensitising, silver fluoride (AgF) at neutral pH may also have value as a minimally invasive dental caries treatment. This study explored the effectiveness of two AgF products (AgF/KI and AgF/SnF2) when used in adult patients with special needs (SN) who had high caries risk and salivary gland hypofunction. METHODS: This split-mouth clinical study, over two appointments 3-months apart, compared the impact of a single application of AgF/KI (Riva Star Aqua, SDI) and AgF/SnF2 (Creighton Dental CSDS, Whiteley) on matched carious lesions in the same arch, by clinical visual-tactile (cVT) assessment of caries status and laser fluorescence (LF, DIAGNOdent) evaluation of bacterial load in the lesions, using repeated measures analysis. RESULTS: Twelve participants were recruited in the study. A total of 56 teeth (28 pairs) were included. Both AgF products gave a significant decrease in caries activity as measured by cVT (P < 0.0001) and LF (P = 0.0027). There were no statistically significant differences between the two AgF treatments, with response rates for improvements in active lesions of 92% in the AgF/KI arm, and 96% in the AgF/SnF2 arm. There was no effect of tooth type, lesion type, arch type, plaque metabolism and plaque area at the site level on outcomes, nor was there a clustering effect of sites in a patient level analysis. Overall, LF was superior to cVT for detecting lesions that still progressed despite treatment (P = 0.0027). CONCLUSION: A single application of AgF/KI or AgF/SnF2 has high predictability (over 90%) for achieving arrest in active caries lesions in adult patients with SN and high caries risk. Clinical assessment should use visual-tactile examination combined with LF readings to detect lesions that are still progressing and that require additional treatments. Future studies should compare these AgF modalities with SDF and explore factors such as time between applications and the need for repeated applications. TRIAL REGISTRATION: The study was registered with the Australian Clinical Trials Registry (ACTRN12621001139864p) on 23/08/2021.

A Bayesian benchmark concentration analysis for urinary fluoride and intelligence in adults in Guizhou, China.

Environmental fluoride exposure has been linked to numerous cases of fluorosis worldwide. Previous studies have indicated that long-term exposure to fluoride can result in intellectual damage among children. However, a comprehensive health risk assessment of fluorosis-induced intellectual damage is still pending. In this research, we utilized the Bayesian Benchmark Dose Analysis System (BBMD) to investigate the dose-response relationship between urinary fluoride (U-F) concentration and Raven scores in adults from Nayong, Guizhou, China. Our research findings indecate a dose-response relationship between the concentration of U-F and intelligence scores in adults. As the benchmark response (BMR) increased, both the benchmark concentration (BMCs) and the lower bound of the credible interval (BMCLs) increased. Specifically, BMCs for the association between U-F and IQ score were determined to be 0.18 mg/L (BMCL1 = 0.08 mg/L), 0.91 mg/L (BMCL5 = 0.40 mg/L), 1.83 mg/L (BMCL10 = 0.83 mg/L) when using BMRs of 1 %, 5 %, and 10 %. These results indicate that U-F can serve as an effective biomarker for monitoring the loss of IQ in population. We propose three interim targets for public policy in preventing interllectual harm from fluoride exposure.

Antibacterial effects of dentifrices against Streptococcus mutans in children: a comparative in vitro study.

Fluoridated dentifrices have antibacterial effects on children's teeth. On the other hand, the side effects encountered with the use of them have led researchers to look for safe alternatives. This study aimed to determine the antibacterial effect of different commercially available fluoride-free dentifrices on Streptococcus mutans (S. mutans) in comparison with different concentrations of fluoridated dentifrices. Study groups comprised of fluoride-free dentifrices, which contain Probiotic (Activated Charcoal Probiotic Dentifrice-Group P), Aloe Vera-Group AV and Salivary Proteins-Group SP. Fluoridated dentifrices containing 1450 ppm fluoride-Control Group 1 and 500 ppm fluoride-Control Group 2 served as control groups. Antibacterial activity was assessed by Minimum Inhibitory Concentrations and agar well diffusion assays on S. mutans. Biofilm inhibition assay was performed with dentifrices, which had antibacterial activities, and a negative control phosphate-buffered saline (Group PBS) on sterile hydroxyapatite discs against S. mutans. Statistical evaluation was performed. Only group AV showed an antibacterial effect on S. mutans, while control groups showed a similar antibacterial effect. The mean number of viable bacteria present in S. mutans biofilm in Control Group 1 and 2 and Group AV were statistically significantly lower than that in Group PBS, but there were no statistically significant differences between Control Groups and Group AV. Antibacterial activity of commercial dentifrices against S. mutans may be exerted by antibacterial components other than fluoride. Aloe vera-containing toothpaste showed an antibacterial effect on S. mutans, although not as much as the fluoride-containing toothpastes in the control groups. However, further in vivo and long-term studies are required.

Unexpected sequel to the application of silver fluoride followed by stannous fluoride to an open carious lesion in a primary molar: A case report.

OBJECTIVES: The use of silver fluoride followed by stannous fluoride was designed for the treatment of open carious lesions in primary molars in dental outreach programs. However, during the COVID-19 pandemic when aerosol-producing procedures were inadvisable, one dental location started using it as the first stage in a two-visit restorative procedure for carious primary molars. If the gap between the fluoride application and the restoration placement stages was around 3-5 weeks it was noticed that a black friable crust appeared on the caries surface. To investigate further a normally discarded crust from one patient was retrieved and sent for analysis. MATERIALS AND METHODS: Two techniques suitable for identification and preliminary analysis of material of unknown composition, scanning electron microscopy and energy dispersive spectroscopy (EDS) were used. The only preparation was that the specimen was dried and coated beforehand. RESULTS AND CONCLUSIONS: This preliminary examination showed two unexpected findings. The first was that the crust surface indicated a possible dentine derivation as it was covered with reasonably evenly spaced holes. In addition, the EDS spectrum showed it to be, at least, partially mineralized. The second unexpected finding was that the surface was coated with electron-dense particles. The size of the particles and the EDS spectrum pointed to the likelihood of the majority of them being nanosilver. These unexpected findings suggest a possible new direction for research.

Remineralization potential of dentifrices with calcium sodium phosphosilicate and functionalized tri-calcium phosphate in the deeper incipient carious lesions: An in vitro study.

OBJECTIVES: This study evaluated the remineralization potential of calcium sodium phosphosilicate and functionalized tri-calcium phosphate (f-TCP) dentifrices in deeper incipient carious lesions (ICLs). MATERIALS AND METHODS: Artificial ICLs were created by placing premolars into demineralizing solutions. Teeth were randomly assigned into four groups: calcium sodium phosphosilicate (Group 1), f-TCP (Group 2), 1450 ppm fluoride (Group 3), and distilled water (Group 4), which were subjected to 10-day pH cycling. Mineral density (MD) was assessed using microcomputed tomography (Micro-CT), while hardness (H) and elastic modulus (EM) were assessed using nanomechanical testing. RESULTS: MD % gain was higher in Groups 1-3 than in Group 4. In addition, Groups 1 and 2 exhibited significantly higher MD % gain than Group 3. Also, Groups 1-3 showed significantly higher EM and H values than Group 4 in the outer enamel area; yet, Groups 1 and 2 displayed significantly higher EM and H values than Groups 3 and 4 in the inner enamel. CONCLUSIONS: The MD, EM, and H of ICLs significantly increased with the addition of calcium sodium phosphosilicate or f-TCP to fluoridated dentifrices compared to standard fluoride dentifrices. The added active ingredients remineralized the deeper parts of the ICLs, while remineralization at the lesion surface was similar between tested dentifrices.

Efficacy of a stannous fluoride dentifrice for relieving dentinal hypersensitivity in Chinese population: an 8-week randomized clinical trial.

OBJECTIVES: To compare the effectiveness of using a 0.454% stannous fluoride-containing dentifrice twice daily in relieving dentinal hypersensitivity (DH) in a Chinese population. MATERIALS AND METHODS: This was a single-centre, randomized, controlled, examiner-blind, three-treatment-arm, parallel-group study in participants with clinically diagnosed DH. Subjects who met inclusion criteria (n = 197) were randomly allocated into 3 groups: test group (n = 66)-using a 0.454% stannous fluoride-containing dentifrice twice daily; positive control group (n = 64)-using a 5.0% calcium sodium phosphosilicate-containing dentifrice twice daily; negative control group (n = 67)-using a 1150 ppm of NaF dentifrice twice daily. Status of DH was assessed at week 4 and week 8 by the same independent examiner. Changes from baseline in Schiff sensitivity score, tactile threshold and Dentine Hypersensitivity Experience Questionnaire (DHEQ) score were analysed using analysis of covariance models. The DHEQ evaluated subject-perceived oral health-related quality of life (OHRQoL). RESULTS: Statistically significant improvements in mean Schiff scores (p < 0.0001 for all products at Weeks 4 and 8), tactile threshold (p < 0.0001 for test and negative control at Weeks 4 and 8: Week 4 p = 0.0040 and Week 8 p < 0.0001 for positive control) and all DHEQ scores (p < 0.01 for all groups) were observed. No statistically significant differences were observed in the adjusted mean between all dentifrices at both timepoints, potentially driven by a placebo effect. Forty-two treatment-emergent adverse events (TEAEs) were reported (n = 32 subjects), with 2 serious AEs (n = 1) in the test group. TEAEs were not considered treatment-related. CONCLUSIONS: All groups demonstrated statistically significant improvements in Schiff score, tactile threshold and OHRQoL. However, due to a possible placebo effect in the negative control, there were no statistically significant differences between the dentifrices. CLINICAL RELEVANCE: This study adds to the growing research exploring why the placebo effect is a common phenomenon in DH studies. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04950465.

Anhydrous and Stereoretentive Fluoride-Enhanced Suzuki-Miyaura Coupling of Immunomodulatory Imide Drug Derivatives.

Immunomodulatory imide drugs form the core of many pharmaceutically relevant structures, but Csp2-Csp2 bond formation via metal-catalyzed cross coupling is difficult due to the sensitivity of the glutarimide ring ubiquitous in these structures. We report that replacement of the traditional alkali base with a fluoride source enhances a previously challenging Suzuki-Miyaura coupling on glutarimide-containing compounds with trifluoroborates. These enabling conditions are reactive enough to generate these derivatives in high yields but mild enough to preserve both the glutarimide and its sensitive stereocenter. Experimental and computational data suggest a mechanistically distinct process of π-coordination of the trifluoroborate enabled by these conditions.

Associations between school-based fluoride mouth-rinse program, medical-dental expense subsidy policy, and children's oral health in Japan: an ecological study.

BACKGROUND: Dental caries are a common non-communicable disease among children. As a public health measure at the prefectural level, school-based fluoride mouth-rinse (S-FMR) program, medical/dental expense subsidy policies, and other factors may reduce the incidence of dental caries and tooth loss. Prefectures focusing on promoting oral health policies may promote both, but the interaction effect of implementing both subsidy policies and S-FMR at the prefectural level on caries prevention has not yet been examined. METHODS: We conducted an ecological study using two-wave panel data, prefecture-level aggregated data in Japan for 2016 and 2018. Coefficient and 95% confidence intervals (CI) were calculated for the dependent variables for oral health using mixed-effects linear regression analysis adjusted for possible confounders. Two dependent variables were used; the standardized claim ratio (SCR) of deciduous tooth extraction and 12-year-olds' decayed, missing, or filled permanent teeth (DMFT). Four independent variables were S-FMR, the SCR of dental sealants, prefectural income per person, and subsidy policy in three models: co-payment until children enter elementary school (n = 23), no co-payment until children enter elementary school (n = 7), and co-payment continuing beyond elementary school (n = 17). The effects of six interaction terms, each representing a unique pairing from the four independent variables, were individually calculated. RESULTS: S-FMR was negatively associated with the SCR of deciduous tooth extractions and DMFT (coefficient = -0.11, 95% CI -0.20; -0.01 and coefficient = -0.003, 95% CI -0.005; -0.001, respectively). No co-payment until children enter elementary school was positively associated with the SCR of deciduous tooth extraction compared to co-payment until children enter elementary school(coefficient = 11.42, 95% CI 3.29; 19.55). SCR of dental sealants was positively associated with the SCR of deciduous tooth extractions (coefficient = 0.12, 95% CI 0.06; 0.19) but negatively associated with DMFT (coefficient = -0.001, 95% CI -0.003; -0.0001). Per capita prefectural income was positively associated with the SCR of deciduous tooth extractions(coefficient = 0.01, 95% CI 0.001; 0.02). No interaction was found between S-FMR and the subsidy policy at both outcomes. CONCLUSION: High S-FMR utilization and no co-payment until children enter elementary school were associated with fewer deciduous tooth extractions. Also, S-FMR and dental sealant were associated with decreased DMFT.

Prenatal exposure to environmental toxins and comprehensive dental findings in a population cohort of children.

Environmental toxins are known to have many impacts on growth and development in humans, starting in utero. Alterations in amelogenesis, caused by chemical and physical trauma that occur during the antenatal, perinatal and postnatal time periods, may result in developmental defects in deciduous and permanent tooth enamel, as demonstrated in animal studies. These defects can be clinically visible and result in a variety of morphological and functional problems in the dentition. Since enamel does not remodel after formation, it may serve as a permanent record of insults during organ development.Our primary purpose was to investigate any possible relationship between intrauterine exposure to endocrine disrupting chemicals (phenols and phthalates) and developmental defects in enamel in children, while also accounting for fluoride exposure. Our secondary purpose was to report descriptively on findings from comprehensive dental examinations performed on 356 children that were drawn from the general paediatric population. A cohort of children from the Utah Children's Project (N = 356) that had full medical exams, comprehensive medical and family histories and available biospecimens were given extraoral and intraoral examinations. They also completed an oral health questionnaire. Standardized intraoral photographs were taken of the teeth and viewed by standardised examiners and the dental observations were recorded for a full inventory of findings, including: tooth morphology, caries, restorations, colorations, attrition, erosion, fractures and hypomineralization. Perinatal maternal urine samples were assessed for the concentration of fluoride, phenols and phthalates, including bisphenol A (BPA).Pairwise statistical analyses were done to correlate the dental findings with one another and with the presence of environment chemicals found in the urine samples. Hypomineralization was the most common finding (96% of children; 37% of deciduous teeth, 42% of permanent teeth), consistent with molar incisor hypomineralization (MIH) described in other human populations. No consistent correlations were seen between dental findings and the presence of phenols and phthalates in prenatal urine, but the number of samples available for the assessment was limited (n = 35).In conclusion, we found a high proportion of dental hypomineralization in a population based paediatric cohort, but did not find an association with prenatal exposure to phenols and phthalates.

Adaptive responses of the ileum of NOD mice to low-dose fluoride: A proteomic exploratory study.

Fluoride (F) has been employed worldwide to control dental caries. More recently, it has been suggested that the consumption of low doses of F in the drinking water may reduce blood glucose levels, introducing a new perspective for the use of F for the management of blood glucose. However, the exact mechanism by which F affects blood glucose levels remains largely unexplored. Given that the small gut plays a pivotal role in glucose homeostasis, the aim of this study was to investigate the proteomic changes induced by low doses of F in the ileum of female nonobese-diabetic (NOD) mice. Forty-two female NOD mice were divided into two groups based on the F concentration in their drinking water for 14 weeks: 0 (control) or 10 mgF/L. At the end of the experimental period, the ileum was collected for proteomic and Western blot analyses. Proteomic analysis indicated an increase in isoforms of actin, gastrotropin, several H2B histones, and enzymes involved in antioxidant processes, as well as a decrease in enzymes essential for energy metabolism. In summary, our data indicates an adaptive response of organism to preserve protein synthesis in the ileum, despite significant alterations in energy metabolism typically induced by F, therefore highlighting the safety of controlled fluoridation in water supplies.

Characterisation of experimental flowable composites containing fluoride-doped calcium phosphates as promising remineralising materials.

OBJECTIVE: Remineralising composites with antibacterial properties may seal the cavity and prevent secondary caries. This study aimed at developing experimental flowable composites containing different concentrations of fluoride-doped calcium phosphate fillers and evaluating their remineralising and antibacterial properties. METHODS: Experimental resin-based composites containing different concentrations (0-20 %) of fluoride-doped calcium phosphate fillers (VS10/VS20) were formulated. The release of calcium (Ca), phosphate (PO) and fluoride (F) ions was assessed for 30 days. Remineralisation properties were evaluated through ATR-FTIR and SEM/EDX after storage in simulated body fluid (SBF). The metabolic activity and viability of Streptococcus gordonii was also evaluated through ATP, CFU and live/dead confocal microscopy. The evaluation of specific monomer elution from the experimental composites was conducted using high-performance liquid chromatography (HPLC). RESULTS: The composites containing VS10 showed the highest release of Ca, those containing VS20 released more F over time (p < 0.05), while there was no significant difference in terms of PO ions release between the groups (p > 0.05). A quick 7-day mineral precipitation was observed in the tested composites containing VS10 or VS20 at 10 %; these materials also showed the greatest antibacterial activity (p < 0.05). Moreover, the tested composites containing VS10 presented the lowest elution of monomers (p < 0.05). CONCLUSIONS: Innovative composites were developed with low monomers elution, evident antibacterial activity against S. gordonii and important remineralisation properties due to specific ions release. CLINICAL SIGNIFICANCE: Novel composites containing fluoride-doped calcium phosphates may be promising to modulate bacteria growth, promote remineralisation and reduce the risk of cytotoxicity related to monomers' elution.

The effect of combined use of resin infiltration with different bioactive calcium phosphate-based approaches on enamel white spot lesions: An in vitro study.

OBJECTIVES: This in vitro study aimed to evaluate the effect of resin infiltration combined with casein phosphopeptide-amorphous calcium phosphate with fluoride (CPP-ACPF) or bioactive glass (BAG) on the stability of enamel white spot lesions (WSLs) treatment. MATERIALS AND METHODS: Eighty-four enamel blocks were prepared from the buccal surfaces of sound human premolars. All enamel blocks were placed in a demineralisation solution for 3 days to establish the artificial enamel WSLs. Enamel blocks with WSLs were randomly divided into three groups (n = 28 each group): RI/B: one-off resin infiltration followed by twice daily BAG treatment; RI/C: one-off resin infiltration followed by twice daily CPP-ACPF treatment; RI: one-off resin infiltration treatment only (as control) and subjected to pH cycling for 7 days. Surface morphology, elemental analysis, crystal characteristics, surface roughness and microhardness of enamel surfaces were investigated by scanning electron microscopy and energy-dispersive spectrometry observation, X-ray diffraction (XRD), atomic force microscope and Vickers' hardness testing, respectively. RESULTS: Mean values of the surface roughness (mean±standard deviation (nm)) were 24.52±5.07, 27.39±5.87 and 34.36±4.55 for groups RI/B, RI/C and RI respectively (p = 0.003). The calcium to phosphate ratios were 1.32±0.16, 1.22±0.26 and 0.69±0.24 for groups RI/B, RI/C and RI respectively (p < 0.001). XRD revealed apatite formation in all three groups. The mean enamel surface microhardness (kg/mm2) of the groups were 353.93±28.49, 339.00±27.32 and 330.38±22.55 for groups RI/B, RI/C and RI respectively (p = 0.216). CONCLUSIONS: Resin infiltration combined with CPP-ACPF or BAG remineralisation appears to improve the surface properties of WSLs. CLINICAL SIGNIFICANCE: The combination of resin infiltration and CPP-ACPF/BAG remineralisation may be a potential treatment for the management of the WSLs.

Carbazole and Quinazolinone Derivatives from a Fluoride-Tolerant Streptomyces Strain OUCMDZ-5511.

Six new 9H-carbazole derivatives (1-6) and nine previously reported compounds (7-15) were isolated from a fermented solid medium of the Thailand mangrove-derived Streptomyces strain, OUCMDZ-5511, under fluoride stress. Compounds 2-5, 12, and 15 were exclusively present in the fluoride-supplemented fermentation medium, while compounds 7-9, 13, and 14 were newly discovered natural products. The molecular structures of the compounds were identified by a spectroscopic analysis. The new compound 2 displayed antiquorum sensing activity against Chromobacterium violaceum ATCC 12472 by reducing the violacein production and inhibiting the biofilm formation in a concentration-dependent manner. The study revealed that compound 2 could be a novel potential inhibitor of quorum sensing.

Riboflavin Attenuates Fluoride-Induced Testicular Injury via Interleukin 17A-Mediated Classical Pyroptosis.

Male reproductive toxicity of fluoride is of great concern worldwide, yet the underlying mechanism is unclear. Pyroptosis is a novel mode of inflammatory cell death, and riboflavin with anti-inflammatory properties has the potential to protect against fluoride damage. However, it is unknown whether pyroptosis is involved in fluoride-induced testicular injury and riboflavin intervention. Here, we first found that riboflavin could alleviate fluoride-caused lower sperm quality and damaged testicular morphology by reducing pyroptosis based on a model of ICR mice treated with NaF (100 mg/L) and/or riboflavin supplementation (40 mg/L) via drinking water for 13 weeks. And then, together with the results of in vitro Leydig cell modelsm it was confirmed that the pyroptosis occurs predominantly through classical NLRP3/Caspase-1/GSDMD pathway. Furthermore, our results reveal that interleukin-17A mediates the process of pyroptosis in testes induced by fluoride and riboflavin attenuation according to the results of our established models of riboflavin- and/or fluoride-treated IL-17A knockout mice. The results not only declare a new mechanism by which fluoride induces testicular injury via interleukin 17A-mediated classical pyroptosis but also provide evidence for the potential clinical application of riboflavin as an effective therapy for fluoride toxicity.

On characterization of entropy measure using logarithmic regression model for Copper(II) Fluoride.

The versatile uses of Copper(II) Fluoride (CuF2) are well known; these include its usage as a precursor in chemical synthesis as well as its contribution to the creation of sophisticated materials and electronics. There are interesting opportunities to study the interactions between these elements because of their unique crystal structure, which contains copper ions and fluoride anions. Its potential in optoelectronic devices and conductive qualities also make it a viable material for next-generation technologies. To better understand the structural properties of CuF2 and how they affect its entropy, we present new Zagreb indices in this study and use them to calculate entropy measures. We also build a regression model to clarify the relationship between the calculated indices and entropy levels. The findings of our investigation offer significant understanding regarding the ability of the suggested Zagreb indices to extract meaningful content and their correlation with entropy in the context of CuF2. This information is important for understanding CuF2 alloys and for exploring related complex materials.